Skin Blemishes: what they are, what causes them and how to tackle them

Skin blemishes are caused by excessive melanin production.  

They consist of patches where the skin’s colouring is different, and are also described as “skin dyschromia”. The most common types are darker than the surrounding area, which is to say that they are forms of hyperpigmented dyschromia or brown blemishes, an increasingly common problem, particularly among women.

Melanin and the formation of blemishes

Skin colour is determined by the presence of melanin, a pigment produced by certain specific cells called melanocytes, found in the deepest layer of the epidermis.

The process behind skin pigmentation (melanogenesis) is extremely complex: it involves the transformation of an amino acid, L-Tyrosine, into melanin, after which it is distributed in the form of small granules from the melanocytes to the surrounding epidermal cells, in a horizontal fashion. The result is an even, uniform spread of the pigmentation.

This is a continuous process, which produces two types of skin pigmentation (colouration):

  • constitutive pigmentation, which refers to the colour of an individual’s “complexion”
  • facultative pigmentation, generally known as a tan, caused by UV radiation stimulating the activity of the melanocytes following exposure to the sun.

When excess melanin is produced it tends to spread in a vertical fashion rather than horizontally, meaning it tends to concentrate and accumulate only in certain restricted areas of the skin, creating brown blemishes or hyperpigmented dyschromia where the colouring is darker than the surrounding skin.

Regardless of age or complexion, the appearance of brown blemishes is an increasingly common aesthetic imperfection which can cause considerable distress, particularly given that they often appear on the face.

Types of brown blemishes on the skin

Two main types of skin blemishes can be identified:

LOCALISED blemishes such as solar lentigos, age spots and post-imperfection marks (e.g. acne), which generally have the following characteristics:

  • a round or oval form
  • generally well-defined outlines
  • appear in isolation or in small groups
  • affect the face, hands and décolletage

EXTENSIVE blemishes such as melasma and chloasma gravidarum, which typically have the following characteristics:

  • an irregular form
  • outlines are not well-defined
  • sprawling (giving the impression of a map)
  • affect the cheeks, the area above the upper lip and the forehead

What causes skin dyschromia?

Skin dyschromia can be hereditary, such as nevi (moles) and freckles, for example, or acquired.

In cases of acquired dyschromia, i.e. the blemishes which may appear over the course of our lives, the excessive production of melanin — which has been identified as the main cause of blemishes on the face and the back of the hands — can be linked to a variety of factors:

  • exposure to UV rays (solar and artificial)
  • hormonal changes, such as pregnancy, the use of contraceptives, or hormone therapy during menopause
  • applying/taking photosensitising substances, such as certain medications or topical formulations
  • acne scars
  • skin ageing

To find out more, you can read our articles:

Hypersensitive and acne-prone skin in the sun
Your skin during pregnancy
Skin ageing

How can skin dyschromia be treated?

type of blemish, localised or extensive. It must also be borne in mind that this treatment always takes some time, as its effects are only visible after the completion of the skin’s normal renewal process, which lasts about 4 weeks.

Moreover, any treatment of skin blemishes must be combined with adequate protection of the skin from UV rays.

It is possible to avail of cosmetic dermatology treatments, such as laser therapy, peels and pulsed light treatments, for example. However, these must always be recommended and carefully monitored by a specialist, and in any case do not always succeed in completely resolving the problem. A more realistic aim, therefore, is to achieve a notable decrease in the visibility of the blemish and to restore a more even complexion with greater radiance.

The main piece of advice which can help in achieving this goal is to follow a specific daily routine from cleansing to treatment, combining a variety of effects:

  • stimulating cell turnover to regenerate the surface layers of the skin
  • effective protection from UV rays
  • inhibiting melanin production and distribution.  

In the short term, however, it can also be very helpful to use corrective make-up with a camouflage effect to minimise or simply disguise the presence of skin blemishes.

For more details on how to treat dyschromia, read our article: Skin Blemishes: how to treat them

To learn more about corrective make-up, read the article: Camouflage, what it is and how to apply it